Has your doctor ever advised you to use sunscreen? Chances are, the answer is no.

In fact, out of 18.3 billion doctor visits over nearly 21 years, sunscreen was recommended to patients only 12.83 million times, a new study finds. That works out to only 0.07% of visits.

OK, you’re thinking, surely doctors did a better job when they were seeing patients for a skin-related disease like melanoma or actinic keratosis. And indeed, they were 12 times more likely to mention sunscreen to these patients. But that still added up to only 0.9% of doctor visits. That’s right – less than 1%.

What’s going on here? Are doctors not aware that sunscreen protects people from UV radiation, the damaging rays that are the primary cause of melanoma and other skin cancers?

And yet, when researchers from the Center for Dermatology Research at Wake Forest School of Medicine in North Carolina examined data from the CDC’s National Ambulatory Medical Care Survey, they found that dermatologists mentioned sunscreen in only 1.6% of patient visits. When seeing patients with skin cancer or a history of the disease, sunscreen came up only 11.2% of the time. And dermatologists are the ones who are experts on keeping skin healthy.

Family medicine doctors and general practitioners discussed sunscreen only 0.03% of the time; internal medicine doctors did so 0.01% of the time; and pediatricians did so 0.01% of the time. All other doctors advised sunscreen use in 0.002% of patient visits.

One of the things that the researchers found most troubling was the fact that children (and their parents) were so rarely advised to use sunscreen. When they analyzed the data by age group, the researchers found that children under 10 were the least likely to be counseled about sunscreen use.

“Children and adolescents get the most sun exposure of any age group, as they tend to spend much of their time playing outdoors,” the study authors noted in their report, published online Wednesday by JAMA Dermatology. “Up to 80% of sun damage is thought to occur before age 21 years, and sunburns in childhood greatly increase the risk for future melanoma.”

Ironically, patients in their 70s were the most likely to discuss sunscreen with their doctors – the topic came up in 21.8% of patient visits, the study found. That’s probably because patients in this age group often have visible signs of sun damage, the researchers found.

For those of us who aren’t hearing it from our doctors, here’s what the study authors recommend:

* Avoid the sun and stay in the shade, particularly from 10 a.m. to 4 p.m.